Lid latch and interlock



Filed April .1, 1967 Nov. 5, 1968 s. L. MCMILLAN 3,408,834

LID LATCH AND INTERLOCK 5 Sheets-Sheet l INVENTOR. STEPHEN L. M MILLAN BY @M H \S ATTORNEY S. L M MILLAN ID LATCH AND INTERLOCK Nov. 5, 1968' 5 Sheets-Sheet Filed April I, 1967 INVENTOR. STEPHEN L M MILLAN ms ATTQRMEY Nov. 5, 1968 s 1.. M MILLAN LID LATCH AND INTERLOCK 5 Sheets-Sheet 5 INVENTOR. STEPHEN L. M Mi LLAN ATTORNEY United States Patent O ABSTRACT OF THE DISCLOSURE An automatic fabric washer including means for insuring that the washer door is-closed during-centrifugal extraction. In the washer a door closure indicatormember is moved out of the washer access :opening by closing-the washer door, a lock member is movable to aposition restraining. the door in its closed position and a latch member is movable to a position preventing the lock member being movedfrom itsdoor restraining position. A first switch is closed in response to the indicator. and lock membersbeing in the positions described and a second switch is closed when the washing machine. is centrifugally extracting liquid. Power .means are energized when both the switches are closed to move the latch member to its position blocking the lock member.

Summary of the invention An object of this invention is to provide animproved lid latch and interlock mechanism for an automatic washer.

'Another object of this invention is to provide animproved lid latch and interlock mechanism which is effective to positively lock the access door of .a washing machine closed. r

A further object is to provide such an improved lid latch andinter-lock mechanism which-is so constructed as to discourage attempts to fool it.

In accordance with one aspect of the invention there is provided a fabric washing machine including a housing with-washing means in the housing to wash fabrics in a suitable fluid and centrifugally extract the fluid from the fabrics; The housingiincludes va door movable. between an open position and a closed position and a door'closure indicator member biased to a first position and'movable to a second position in response to the door being closed. A=door loc-k member ismovable between a first position .free ofsthe door and a second position restraining the door in-its closed position. A latch-member is movable betweena first position free of the door lock member and a second position preventing the door. lock memberbeing moved from its second position. The machine also includes means responsive to the position of the indicator and lock members .for energizing the washing means-for centrifugal extraction only whenvboth these members are in their second positions and power means formoying the latch member to its second position when TDesc ription of the drawings The features'which are believed to be novel are" set forthwith particularity in the appended claims. The in- Patented Nov. 5, 1968 "ice FIGURE 3' is-an enlarged, fragmentary plan view of the machine of FIGURE*1 FIGURE 4 is a view taken'along'line'4 4 of FIG- URE3;and 1' FIGURE 5 is a simplified electrical circuit diagram of a'circuit'suitable' for use in the machine of FIGURE 1.'

Description of the preferred embodiments Referring now to FIGURE 1, there is shown a fabric or clothes washing'machinelfl incorporating one embodiment of this invention. The-'machine is provided with an outer-appearance cabinet 11 including a top 12 and'a bottom bulkhead 13.'The bottom bulkhead 13 is welded or otherwise s'ecuredwithin the appearance cabinet 11 to provide a water collection "compartment-14 andama chi'nerycompartmentlS."Disposed within the machinery compartment 15 is a frame 16 "mounted for gyratory charged by the pump 'to a drain conduit 22 adapted for vention itself, however, both asto its organization and discharge to a stationary tub or drainline.

A transmission assembly.23 is also mounted on frame 16. The transmission is operated by motor 18 and pulley 20 through a belt .24 which connects pulley 20 to a pulley 25 arranged in driving relationship to the transmission. A shaft 27 extends upwardly from transmission 23 and is secured at its upper end (not shown) to an agitator 28, which may be of the conventional type having a centerpost 29 and washing vanes 30. As is conventional in washing machines, transmission 23 is of the type which, when motor 18operates in one direction, will cause oscillation of shaft 27.This in turn drives agitator 28 so that it oscillates in a horizontal'plane and provides a washing action when there is liquid contained within a basket 31. Rotation of motor 18 in the opposite direction causes transmission 23 to rotate shaft 27 continuously in a single direction, while at the same time like rotation of a sleeve 32 also connected to be operated by the transmission 23 is provided. Sleeve '32 is secured to a fixture 33 on which basket 31 is mounted. Consequently, when shaft 27 and sleeve 32 rotate together continuously, the agitator 28 and basket 31 are rotated as a unit to effect centrifugal extraction of liquid from fabrics or clothes contained in the basket. The centrifugal force causes the liquid to pass out-through openings such as those shown at 34, which are provided for that purpose. The liquid drains into compartment 14 from which it. is taken by pump 21 and expelled to the drain or stationary tub. A suitable clothes guard (not shown) may be provided to retain fabrics in basket 31 while, at the same time, the liquid is allowed to escape.

Thus rotation of motor 18 in'one direction causes oscillating operation of agitator 28 for washing and rinsing of fabrics in the liquid, while rotation of the motor in the other direction causes high speed rotation of the agitator 28 and basket 31 together for centrifugal extrac tion of the liquid.

A suitable water inlet 35 permits entry of water into the basket 31. The passage of water through inlet 35 iscontrolled by conventional solenoid operated valves of a construction well known to those in the art. The control of these valves is described in connection with the discussion below of FIGURE 5. I I

Supported at the back and on top of the washing machine is a control panel 36 including control dial 37 and a multiple. positionrotary. switch .38, which may be usedv to set the operating components of the machine to perform :a desired cycle of operation.

Fabric washing machines; whetherthey be the vertical agitator type' illustrated in FIGUREI or the tumbler type, have an appropriateopening for theinse rtion or removal of the fabrics to be washed. Machine is provided with such an opening39; in the top 12. The machine further includes a door or lid 40 which is pivoted along. one edge as illustrated at 41 so as to be manually movable between a closed position covering opening 39, as illustrated in FIGURE 1, and an :open positionexposing the opening 39. Such doors are :open beforeand after the sequence of operationof the machine for; the insertion and removal of fabrics and are generallykept closed during the sequence. of operation. Duringcentrifugal-liquid extractionthe basket 32 and agitator 28 arerotated at a. rather high speed. Thus,-it is-desirable-to-latch the lid 40 closed prior: to any centrifugal extractiomoperation and to interlock the lid 40 tandmotor- 18so that the extraction. operation is automatically terminated if the lid is opened or, preferably, toinsure that the lid cannot be opened until centrifugal extraction is terminated. 7

Referring particularly to FIGURES 2 through 4 there is shown a lid latch and interlock mechanism for accomplishing this purpose. This mechanism includes a first elongated member (a door or lid closure indicator) 41 which is biased into a first position extending into the opening 39 by a spring 42 which is mounted between the mem ber 41 and a wall 43. The wall 43 forms a protected compartment for the lid latch and interlock mechanism at the top of the water collection compartment 14. One end of the spring 42 is received in a recess 44 in member 41 and the other end is received in a recess 45 in wall 43. t

The spring 42 biases the member 41 to the left, as seen in FIGURE 2, so that the ramp 46 formed at the outer of the door or lid 40, as the door is closed. This causes the member 41 to be cammed or moved to the right toa second position, as seen in FIGURE 2.

The mechanism also includes a second elongated member (door or lid lock) 48 which is mounted over the lid closure indicator 41 and is biased to extend into the opening 39 by a spring 49. One end of the spring 49 is received in a recess 50 formed in a down turned edge 43a of the wall 43 and its other end is received in a recess 51 formed in the end of member 48. The end of member 48 extending into opening 39 is provided with a ramp 52 which is engaged by the edge 47 of the door 40 as the door is moved from its open to its closedposition. Thus, in a manner similar to member 41, member 48 is carnmed out of the way by door 40 as the door is closed. However, once the door has passed, the member 48 is moved to the left (as seen in FIGURE 2) by the spring 49 so that the lid lock 48 overlies the door 40 and holds the door in its closed position. In order to free the door so that it may be opened, the lid lock 48 is provided with a projecting tab or handle 53 which extends through an opening 54in the top 12. The user may grasp the handle 53 and move the lock 48 to the right, freeing the door 40 so that it may be opened.

As another portion of this invention there is provided a first or lid switch 55 which is closed only when door 40 is locked in its closed position. The switch 55 may be of the type which is biased to a switch open position and is closed by moving an actuator such as that shown at 56. The switch automatically returns to its open condition when the closing force is removed from the actuator. As

seen in FIGURE 3, the switch 55 is mounted to the side portion 58 having an elongated opening 59 which receives i a pin 60 extending upwardly from a horizontal portion of the wall 43. .With this arrangement the link 57 is free for both sliding and rotary movement about the pin 60. The lid closure indicator 41 is provided with a cam portion 61 and the lid lock 48 is provided with a cam portion 62, which cooperate to form a pair of relatively movable diverging walls. One end 63 of the link 57 is arranged to contact 'cam62 and the other end includes-a downwardly extending pin or-tab 64 arranged tocontact cam 61. With this arrangement of parts thepositioningof the link 57 is controlled by the relative positioning of the cams 61 and 62. With the members-41 and48 in the position shown in FIGURES 2. and 3, ,that is with the lid 49, closed and locked, the cam surfaces are in their closest relative positions and force the link "57 in its extreme position to ward the switch 55. This causes the actuator 56 to be depressed closing the switch. m. .7 H, 'The'body 58 of link 57 is formed along one edge with a pairof angled walls 65 and 66 which converge at an apex 67. With the'lid- 40 closed and'lo'cked the apex 67 is brought into contact with'the actuator 56. This caus'esthe actuator 56 to be depressed toclose the switch 55. If the lid lock 48 is moved out of register with theopening 39, the cam portion 62 will be moved to the right (as seen in FIGURE 3). This allows the link 57 to pivot about pin 60 so that the switch actuator 56 will move ofi. of the apex 67 onto the Wall 66. This allows the internal bias of the switch to open the switch contacts. In a similar manner when the lid closure indicator is moved into the opening 39 by its associated spring 42 when the lid is opened, the cam 61 is moved to the'left (as seen in FIGURE 3). This allows the link 57 to pivot in the other direction about pin 60 and the actuator 56 to ride along wall 65 so that the contacts of the switch 55 are opened. With the arrangement of parts thus far illustrated the switch 55 is closed only when the lid 40 is locked in its closed position. The switch 55 is included in an electrical control circuit, to be described in detail below, so that certain operations of the washing machine may not take place unless the switch 55 is closed.

This mechanism is designed so that theswitch 55 will be closed only when the lid is locked closed, that is when member 41 is moved to the right and member 48 is moved to the left (as seen in FIGURE '2). It will be noted that since lid lock 48 extends over lid closure indicator 41, this arrangement discourages attempts to fool it.

As another portion of this invention there is provided, as part of the latch [and interlock mechanism, means for holding the lid lock in its position retaining the lid closed. For this purposethere is provided a third member or latch 68 which is pivotally mounted on a pin 69 secured in the down turned portion 43a of wall 43. A spring 70 is attached at one end to'the latch and at the other to another portion 43b-of the wall, and biases the latch to a first posiion (shownin the solid line in FIGURE 4) free of the lock 48. A solenoid 71 is provided and is connected to the latch 68 by an operating rod 72. The solenoid acts in opposition to the spring 70, that is whenthe solenoid is energized it pulls on the latch 68 through the operating rod 72 in opposition to the spring 70. The solenoid 71 overcomes the spring force and moves the latch to its other position (shown in dotted line in FIGURE 4), where the latch is interposed between the down turned portion 43a and a foot 73 provided on the end of lid lock 48. With the latch in this position the lid lock 48 may not be moved out of its interfering relationship with the door 40 and securely holds the door in its closed position. When the solenoid 71 is de-energized the spring 70 again moves the latch to its first position, free of the lid lock 48 so that the lidlock may be moved out of interfering relationship with the lid. The operating rod 72 is formed with a spring portion 74 to compensate for any slight misadjustment between the solenoidll and the latch 68i-It also allows the solenoid to pick-up should it be energized when the lock 48 is'in a positioninterfering with the motion of latch 68fThis prevents burn-out of the solenoid. l

Referring nowto FIGURE 5, there is shown, in schematic form, a simplified electric circuit for the machine of FIGURE '1, utilizing the lid latch and interlock mechanism ofv this invention. It will be understood that. many .washing machine features. which do not relate to the invention such as, for instance, sequence control means for .selecting a number of different sequences of operation of the machine, water temperature selecting means, fluorescent lights, etc., have been omitted in order to simplify and clarify the description of the subject matter of this invention. The .circuit is connected across apair-of lines 75 and 75a which, in the usual way, are energized from a source of 120 volt, 60/cycle alternating current power. The connectionof the different components; of the machine across the source of power is controlled by a .switch 76 which is actuated byv axial movement on the dial member 37. When dial37 is moved inwardly, switch 76 is opened and (when the dial is pulledaxially outwardly, the switch is closed so as to connectthe various components of the machine to the source of power. I

A timer motor 77 inconnected acrossthe lines 75 and 75a under control switch 76 and is connected in controlling relationship .to a group of generally circular cams A,' B, C, D, and B. These cams are also controlled by dial 37. In other words, in the conventional way,

the cams maybemanually preset by rotation of the dial to a position for providing the various desired functions of the machine. When it is desired to set the machine in operation the dial 37 is pushed in, opening switch 76 :and then rotated so as toprovide the proper setting for the various cams. The dial then is pulled axially outwardly, closing switch 76 to initiate the sequence of operations; The dial 37 is connected to the timer motor so that when thetirner motor has operated a sufficient periodof time to complete the desired cycle ofoperation the dial 37 will have been rotated sufliciently to be released vand moved inwardly, so as to open switch 76.

Thecam A controls a switch 78 which is in series with the coil 79 of a switch controlling the fiow, of hot water into the machine (the valve not being otherwise shown). Cam B controls a switch 80 in series with the coil -81 of a valve controlling the entry of cold water to the machine. Each valve normally will operate to permit.the entry ofwater when its coil is energizedand to preclude entry of water when its coil is deenergized. Cam C controls a switch 82 which isin series with drive motor 18 so as to control the energization thereof. More specifically switch 82 is connected directly in series with the main winding 83 of motor 18 which, as v is conventional, is a split-phase, resistance-start, induction type motor. Inorder to etfectthestarting of this type of motor, there is required, in addition to the main winding 83, a start winding 84. Start winding 84 is connected in parallel with, main winding 83 by means of a double- .pole, double-throwmotor-reversing switch 85 controlled by cam D. With switch 85 in the position shown, the

switch 88 is closed and when the motor is operating abovethat speed, the switch is closed. The circuit then continues, through the start winding 84 and contacts 89 and 90 of switch 85, and then through a conductor 91, to the other side of main winding 83. Thus, when the switch 82 is closed, the motor 18 may be energized with .windings 84v and 83 in parallel with each other. and: the

motor is able to start in a predetermined direction. As

.the motor comes up to speed, switch.88 is opened by. the

centrifugal, motor-connected. device 92, and the motor .t hen ,continuesto run on the main winding 83 alone.

When contacts 87 and 89 are moved by cam D toengage contacts 90 and 93 respectively, the polarity of the start winding is reversed with respect to the mainwinding. This is because the circuit from switch ,82 proceeds through contacts 93 and 89, the start winding 84, switch 88 and the contacts 87 and 90 to conductor 91. Inother words the connection of start winding 84 is reversed relative to winding 83 so that the motor starts to operate in the opposite direction. The motor will continue to run in the opposite direction on run winding 83 when the centrifugal mechanism 92 opens switch 88 as the motor comes up to speed. 7 i The circuit for the motor 18 may be completed to line a through lid switch 55 or through the contacts 94 and 95 of a switch 96 controlled by cam E, the switch 96 having a third contact 97. I I

A third circuit is provided from line 75 to line 75a and includes the series connection of the coil 98 of solenoid 71. A switch 99, which is also controlled by centrifugal mechanism 92 and contacts 97 and' 95 of switch 96. The switch 99 is constructed andar'rangedto be open whenever the motor 18 is at restor rotating below a predetermined speed andto be closed .by centrifugal mechanism 92 whenever the motor comes up to operational speed. Thus it will be seen that an energizing circuit for the coil 98 of solenoid 71 is energized when switch 76, controlled by dial 37 is closed, motor 18 is rotating at o erational speed, closing switch 99, and contact 95 has moved into engagement with contact 97 in response to appropriate rotation of cam E. In this regard cam E is designed to close contacts 94 and 95 during periods of washing and rinsing and to close contacts 95 and 97 during periods of centrifugal liquid extraction.

If dial 37 is rotated so as to set the various cams for a cycle of operation and is then pulled out so that switch 76 is closed, cam A will have closed switch 78 toenergize coil 79 and permit the entry of hot water into the machine. In series with coil 79 and switch 78. there is a centrifugal switch 100, also controlled by centrifugal mechanism 92. The switch 100 is closed when the drive motor 18 is at rest or operating below a predetermined speed and open when the drive motor is rotating at normal operational speed. This insures that, when the motor starts operation, the entry of water will cease.

The energization of coil 79 continues for a predetermined the fill operation is terminated by cam A opening switch '78 Cam C then closes switch 82 to energize drive motor 18. Since cam E closes contacts 94 and 95 the motor will be energized regardless of whether lid switch 55 is closed. With the particular directionof rotation provided for motor 18 by cam B, the transmission 23 will provide the aforementioned operation of agitator 28 and 'a washing operation will take place. As the motor comes up to speed, centrifugal mechanism 92 opens switch 88, to deenergize start winding 84; opens switch 100 to in sure deenergization of the water inlet valve; arid closes switch 99 in the lid latch interlock circuit.

This washing operation continues until cam C opens switch 82, at which point the drive motor 18"is deenergized and stops.. However, the timer motor 77 continues to operate, causing cam D to reverse the-positioning of switch and cam E to move contact from contact 94 to contact 97. Thereafter cam C recloses switch 82 and motor 18 starts rotating in the opposite direction from before, assuming the door is closed and locked so that lid switch 55 is closed. As previously explained, this causes a centrifugal liquid extraction operation to be provided. This action continues for a predetermined perkid of timer motor operation, at the end of which cam C again, opens switch 82. Thereafter cams'A and B close switches 78 and 80 and, switch .100 is closed because motor 18 is at rest. This setting allows the mixing of hot and cold water and introduction of warm water to the basket 31. After a predetermined period of warm water fill, cams A 'and B open switches 78 and 80, carn D' returns switch 85 to'its agitate position, cam 'E returns'contact 95 to contact 94 and cam C then recloses the switch 82. This energizes drive motor 18 in the agi- ,tation direction of operation and a period or rinse agitation ensuesj At the end of the rinse agitation period, cam C again opens the. switch 82, cam D moves switch 85 to its other position, cam E moves contact 95 to its other position, then cam C recloses switch 82.This again. causes the drive motor 18 to rotate in the centrifugal liquid ext'ractioddirection of operationto remove the rinse water from the basket, again assuming lid switch 55 is closed.

At the conclusion of 'the second extraction operation timer motor 77 will have rotated dial 37 sufliciently that it is released and moved inwardly to cause switch 76 to be opened, this deenergizing the entire circuit.

It will be understood that, while a very basic sequence of operation having a single wash period followed by a centrifugal extraction and a single rinse period followed by a centrifugal extraction has been described, various modifications may be included to provide for sequences of operation including prewashes and multiple rinses and various manual controls may be included for selecting hot, warm or cold water for the various wash and rinse operations.

With this circuit it will be seen that, as drive motor 18 comes up to operational speed, switch 99 is closed and, assuming contacts 95 and 97 are closed in response to proper positioning of cam E as described above, coil 98 for solenoid 71 will be energized to rotate the latch 68 into alignment with the foot 73 of lid lock 48. When coil 98 is energized, lid lock 48 is restrained in its interfering relationship with door 40, preventing the door from being opened, and the lid lock is not released until the drive motor 18 has been deenergized and slows down below the predetermined speed, opening switch 99.

-With many present day washers it may be desired to have a pre-wash, with or without a detergent, and then a wash period with detergent. Many of the machines providing for such cycles do not include automatic detergent dispensers, therefore it would be necessary to be able to open the door 40 during agitation operation of the machine in order to insert detergent. Switch 96 and switch 55 are interconnected to enable the door or lid 40 to be openedduring periods of agitation and to insure the lid .is locked closed during centrifugal extraction. The operation of cam E is integrated with the other cams so as to close contacts 94 and 95 during rotation of motor 18 in the agitation direction and close contacts 95 and 97 during rotation of the motor in the centrifugal liquid extraction direction. Since the circuit through contacts 94 and 95 is in parallel with lid switch 55, lid 40 may be opened during periods of agitation and the machine will continue to operate. Since contacts 95 and 97 are in circuit with coil 98 and not in circuit with motor 18, lid 40 must be locked closed (to close switch 55) before motor 18 will be energized in the centrifugal extraction direction and the lid will be restrained (or latched) in its closed position as long as extraction continues.

The foregoing is a description of illustrative embodi ments of the invention, and it is applicants intention in the appended claims to cover all forms which fall within the scope of the invention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A fabric Washing machine including: (a) a housing;

(b) washing means in said housing to agitate fabrics 8 in a suitable fluid and centrifugally "extract the fluid from the fabrics; "j

(c) said housing "includinga door movable between an open position and a closed position; j

(d) a door closure indicator biased to a first position and movable to a second position in response to said'door being moved to its, closed position;

'(e) a door lock movable between a first position free of said door and 'a second position'restraining said door in its closed position;

(f) a latch movable between a first position freeof said door lock and a second position preventing said door lock being moved from its second positionto its first position;

(g) means responsive to the position-of said indicator and said lock for energizing said washing means-for centrifugal extraction only when' both said indicator and said lock are in their second positions and'power means for moving said latch to its second position "when said washing means is causing centrifugal fluid extraction.

2. A fabric washing machine including:

i (a) abousing; i

(b) electrically energizable washing means in said housing to agitate fabrics in a suitable fluid'and centrifugally extract the fluid from the fabrics;

'(c) said housing defining an opening for loading and unloading fabrics andincluding a door movable to open and close said opening;

(d) a door closure indicator biased to a first position extending into said opening and movable to a'second position in response to said door being moved to its closed position; I 1

(e) a door lock movable between a first position free of said door and a second position in interfering relationship with said door when said door is in its closed position;

(f) an electric power circuit for said washing machine;

' (g) a first connected switch in said'circuit, means actuating said first switch from said indicator and said lock and closing said first switch when said indicator and lock are in their second positions to provide for energization of said washingmeans at least during centrifugal extraction;

(h) a second switch connected in said circuit, said second switch being closed when said washingmeans is causing centrifugal fluid extraction;

(i) alatch biased to a first position free of said lock and movable to a second position preventing said lock being moved from its second position to its first position;

(j) and electrically operated power means connected to said third member and effective, when energized, to move said thirdmember to its second position to hold said lock in interfering relation with said door; said power means being connected in sadi circuit in said lock in interfering relation with said door; said power means being connected in said circuit in series with said second switch. i

3. The invention as set forth in claim 2 wherein said indicator and lock include complementary cam portions, said first switch includes an actuator biased toa switch open position and movable to a switch closed position, and a link is movably mounted for engagement with said cam portions and said actuator; said cam surfaces engaging said link to thereby move said actuator to its switch closed position when said indicator and flock are in their second positions.

4. The invention as set forth in claim2 wherein a third switch means is connected in' parallel with said'first switch during agitation operation of "said washing means and is connected in series with said power means and said second switch during centrifugal extraction operation ,of said washing means. 4

5. The invention as set forth inclairii Z Wherein said lock is mounted in juxtaposition to and outside said indicator and is biased to its second positon wherein it covers said indicator.

6. A fabric washing machine including:

(a) a housing;

(b) electrically energizable washing means in said housing adapted to agitate fabrics in a suitable fluid and centrifugally extract the fluid from the fabrics;

(c) said housing defining an opening for loading and unloading fabrics and including a door selectively movable to open and close said opening;

((1) an elongated door closure indicator biased to a first position extending into said opening and longitudinally movable to a second position in response to said door being moved to its closed position;

(e) an elongated door lock mounted in juxtaposition to and outside said indicator, said lock being longitudinally movable between a first position free of said door and a second position in which it will interfere with the outer surface of said door when said door is closed and biased to its second position to cover said indicator;

('f) said indicator and lock including complementary cam portions forming a pair of relatively movable, diverging walls;

(g) an electric power circuit for said washing machine;

(h) a first switch connected in said circuit, said first switch including an actuator biased to a switch open position and movable to a switch closed position for providing energization of said washing means;

(i) a link movably mounted for engagement with said diverging walls and with said actuator, said link holding said actuator in its switch closed position in response to said indicator and lock being in their second positions, said link freeing said actuator for movement to its switch open position in response to either of said indicator and lock moving to its other position;

(j) a second switch connected in said circuit, said second switch being closed when said washing means is causing centrifugal fluid extraction;

(k) a latch biased to a first position free of said lock and movable to a second position preventing said lock being moved from its second position to its first position;

(1) and electrically operated power means connected to said latch and elfective, when energized, to move said latch to its second position, said power means being connected in said circuit in series with said second switch.

7. The invention as set forth in claim 6 wherein a third switch means is connected in parallel with said first switch during agitation operation of said washing means and is connected in series with said power means and said second switch during centrifugal extraction operation of said washing means.

References Cited UNITED STATES PATENTS WILLIAM I, PRICE, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,408,834 November 5, 1968 Stephen L. McMillan It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 8, line 39, "connected'switch should read switch connected line 55, beginningwith"ho1d"cancel all to and including "switch." in line 59, same column 8, and insert hold said lock in interfering relation with said door; said power means being connected in said circuit in series with said second switch.

Signed and sealed this 10th day of March 1970.

SEAL) LHCSIL:

dward M. Fletcher, Jr. WILLIAM E. SCHUYLER,

nestin Officer Commissioner of Pat ents 

